About as good as a movie can be when it is not meant to be taken too seriously. Lots of good action and entertainment overall. The climax was lacking for me (highlight to read white text): All the badguys from space were lame. Loki was cool, but the rest of the bad guys sucked. Those guys on the flying scooters blew up up cars and buildings, but didn't do shit to any of the Avengers. Same thing with those giant flying monsters. They were completely lame. They were essentially giant flying transports, but really didn't even do as much damage as the guys on flying scooters. They bumped a building here and there, and they were intimidating, but really they didn't threaten anything. Also, how do those things fly? I didn't get the impression that they were magical or god like, so then there should be some sort of physics that helps them fly. But no, no real wings (small fins), no thrusters on the armor, etc. They just glided effortlessly with nothing seemingly keeping them in the air.